The evaluation of the ecological stability of the territory in Slovakia went through a certain development, that led to an obligatory methodology for the evaluation of district in the measures of 1:50 000, that was ratified by the government. The main sources of the methodology of the territorial system of ecological stability (TSES), are the maps of contemporary landscape structure, of the spatial synthesis of the positive and negative factors, the classification of ecological stability of the territory the proposed map of TSES. Part of the TSES is a spatial classification of the ecological stability of the territory (EST) in which the presence, the present state and influence of the positive and negative factors and characteristics on the Landscape are evaluated. The result of this method is the selection of areas with nearly the same degree of ecological stability. Based on this classification it is possible to give the hierarchy of needs for protection and for the utilization of the landscape. There are three bases belonging to the classification of EST: - ecostabilizing elements of the landscape with complementary function of the EST, these are the characteristics of the landscape that support the EST, they are the existing elements of the present landscape structure and the biotopes with ecostabilizing characteristics and propositions - elements of nature and natural sources protection with protecting and developing function of the EST, these are the factors of the landscape which result from the needs of the present and proposed nature and natural sources protection, they contribute to the preserving of the development of EST stress factors of the landscape with lowering or disturbing function of the EST, these are the factors which represent the anthropic load of the environment created by the negative stress factors. The result from the material and non material elements of the present landscape structure and form their synergetic influence. This methodology was verified on the example of the territory of East Slovakia (the district of Humenne, Michalovce, Trebisov and Vranov and Toplou) in the measure of 1:50 000.